1. Field of the Invention:
The present invention relates to a union joint assembly suitable for use in a refrigeration system to join two pipes end to end.
2. Prior Art:
There are known various union joint assemblies of the type described in which a union and a nut, which are fitted respectively around opposed end portions of two pipes, are fastened together to join the pipes with an O-ring sealingly interposed between a flared end of one pipe and an outer circumferential ridge on the other pipe whose end portion is fitted in the end portion of said one pipe. While it is prevented from moving beyond the flared end, the union is allowed to move along the pipe in a direction away from the flared end. With this construction, when joining two pipes to install a cooler unit on an automobile, for example, the union must be moved onto the flared end with the result that assembling of a union joint and hence installation of the cooler unit becomes tedious and time-consuming.
Japanese Utility Model Laid-open Publication No. 57-174214 discloses a somewhat successful union joint assembly which includes an outer circumferential ridge formed on a pipe adjacent to a union carried thereon so as to restrict axial movement of the union to a limited extent between the ridge and a flared end of the pipe. The disclosed union joint assembly is, however, still unsatisfactory in that the union has to be manually brought into engagement with the flared pipe end and held in this condition until the union and the nut is tightly fastened together. The union, if not so threaded with the nut, would corotate with the nut. Another disadvantage of this assembly is in that since the ridge is located near the union, it is difficult to provide a bend adjacent to the union.